Expansible storage receptacles or forage bags have become a common alternative to other ways of storing forage for the specific purpose of its preservation as silage. Different types of equipment have been built in order to fill the storage bags. In filing storage bags the bags must be evenly filled, with pressures equally distributed inside the bag, whether it is at the bottom, the top or the sides. In general terms, the degree of compaction at the bottom of the horizontal bag should be roughly the same as the degree of compaction in the upper part of the bag since it is mostly a horizontal structure with heights that do little to increase pressure. So far, most of the machines that have been built, push the forage into the bag by different means. The simplest is "pushing" in the general area of the bottom of the support for the bag that is being filled in order to generate enough pressure to push up the chopped forage. This way, the agricultural bag is filled by the creation of a very large pressure at the bottom areas. Because of this, large amounts of energy are required to fill the bag and a large difference in pressure, and therefore compaction, is created inside the bag. Several machines have developed a device that resembles a ski ramp that helps with the concept and the necessity to push up the forage. A main point has been missed in the filling process. By filling on one side of the bag (the bottom) there is a much greater pressure in this area (the floor area) of the bag than in the center or the top. This pressure gradient determines that the forage in the bottom is packed at very high pressure with tissue damage, while the forage at the top is not fully packed and leaving enough air to cause spoilage. This causes the forage to ferment unevenly.
Devices are known from the prior art of forage, as discussed above and include the device proposed by Eggenmuller et al. (U.S. Pat. No. 4,046,068. This reference proposes an apparatus for bagging forage including compression roller means with a roller having a shaft with a plurality of rigid tines arranged progressively spiraled around the circumference. Deflector means are provided cooperating with a molding channel, a basket and a roller to assure the absence of gaps within the completed feed to product form.
Johnson et al. (U.S. Pat. No. 4,949,633) and Ryan (U.S. Pat. No. 4,621,666) disclose similar arrangements including a basic process of compaction of forage by the use of different elements, normally a rotor. These patents (including Eggenmuller, U.S. Pat. No. 4,046,069) emphasize the distribution of prongs or teeth that are located along the axle of the rotor. The teeth are described as being located in a spiral sequence along the axle with variable degrees of advance between teeth, being located in an irregular spiral with randomly located teeth or groups of teeth along the axle, or even combinations of all of the above. These references all focus on the concept of pushing the forage out of a receptacle in front of the machine into a shaping tunnel where the agricultural bag is held. Other concepts are considered concerning the application of a braking force (in a back stopping cables or in the main wheels of the machine), wherein different devices are employed as the source of the braking force.